Dynamically release memory about QWebView Error

[yangyunfeizj34]

Hello,
I've been using Qt 4.7.4 for a while and I get a problem: I released memory dynamically,after a few times, the program crashed. I set the QWebView::setAttribute(Qt::WA_DeleteOnCLose);

The first time free memory,no error happened. but after a few, when QWebView show, the program crashed.
VS2010 shows error in "TextBreakIterator* setUpIterator()" .

Someone can help me? Thank you!

The code is:

/main.cpp/ /MyDialog.h/ /MyDialog.cpp/ /MyWebView.h/ /MyWebView.cpp/
@
#include "MyDialog.h"
#include <QtGui/QApplication>
#include <qtextcodec.h>

int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QTextCodec::setCodecForCStrings(QTextCodec::codecForName("gb2312"));
QTextCodec::setCodecForLocale(QTextCodec::codecForName("gb2312"));
QTextCodec::setCodecForTr(QTextCodec::codecForName("gb2312"));
MyDialog *w = new MyDialog;
w->show();
int ret = a.exec();
return ret;
}
@

@#ifndef MYDIALOG_H
#define MYDIALOG_H

#include <qdialog.h>
#include <qstring.h>
#include <qpushbutton.h>
#include <MyWebView.h>

class MyDialog : public QDialog
{
Q_OBJECT

public:
MyDialog(QWidget *parent = 0);
~MyDialog();

QWebView *RetWebView();

public slots:
void slotButtonClicked();
void slotBrowserClose();

private:
QString loginUrl;
QString logoutUrl;
MyWebView *browser;
QPushButton *dispatchButton;
};

#endif // MYDIALOG_H
@

@
#include "MyDialog.h"

MyDialog::MyDialog(QWidget *parent)
: QDialog(parent)
{
dispatchButton = NULL;
dispatchButton = new QPushButton(tr("dispath"),this);
browser = NULL;
connect(dispatchButton,
SIGNAL(clicked()),
this,
SLOT(slotButtonClicked()));
}

MyDialog::~MyDialog()
{
if(browser != NULL)
{
delete browser;
}
}

void MyDialog::slotButtonClicked()
{
if(browser == NULL)
{
browser = new MyWebView;
browser->setAttribute(Qt::WA_DeleteOnClose);
browser->load(QUrl("http://www.yahoo.com"));
browser->show();
connect(browser,
SIGNAL(signalViewClosed()),
this,
SLOT(slotBrowserClose()));
}
}

void MyDialog::slotBrowserClose()
{
browser = NULL;
}

QWebView *MyDialog::RetWebView()
{
return browser;
}
@

@
#ifndef MYWEBVIEW_H
#define MYWEBVIEW_H

#include <QWebView>
#include <qwidget.h>
#include <qevent.h>

class MyWebView : public QWebView
{
Q_OBJECT

public:
MyWebView(QWidget *parent = 0);
virtual~MyWebView();

protected slots:
void closeEvent ( QCloseEvent * event );

signals:
void signalViewClosed();
private:

};

#endif // MYWEBVIEW_H
@

@
#include "MyWebView.h"

MyWebView::MyWebView(QWidget *parent)
: QWebView(parent)
{

}

MyWebView::~MyWebView()
{
int j = 0;
}

void MyWebView::closeEvent ( QCloseEvent * event )
{
emit signalViewClosed();
event->accept();
}
@

[yangyunfeizj34]

I load a new Version Qt 4.8.0,and rebuild this program, the bug disappear miraculous.
Maybe this is a bug in Qt 4.7.4.